1. Field of the Invention
The present invention relates to portable door locks.
2. Background of the Invention
Portable door locks of various designs have been created to secure doors that do not have operable locks, or for travelers or others who wish to personally control access to a room. Such portable door locks can be especially useful in public accommodations, including hotels, dormitories, apartments, and cruise ships.
Prior portable door locks possess several disadvantages. Many are complex and not cost effective to manufacture. Others can be picked, and those with securing pins can be wrenched or pried from the outside by intruders. Some portable door locks include notches, teeth or contain rough edges which may cause injury to the user during installation or removal. A number of portable door locks require special tools to install, or can only work with doorknobs or doorknob shanks of a specific size or shape. Still other portable door locks mar the door when installed, or detract from the door's appearance. Chain locking portable door locks have a low yield strength, and allow the door to be opened several inches, which makes it possible for the chain to be cut by an intruder. Thus, previous portable door locks have not enjoyed large scale commercial acceptance.
Therefore, there is a need for an improved portable door lock that does not damage doors or door frames, and that is simple, secure, compact, strong, lightweight, and inexpensive to manufacture.